In the history of commercial aviation, as flights have covered increasingly longer distances and time on board the aircraft has increased, the boredom of passengers has increased. Bored passengers not only have a less enjoyable flight experience, but they also increase the demands on flight service personnel. From early impromptu card games between passengers to inflight provision of audio entertainment via headsets, entertainment systems on aircraft have progressed to the showing of feature films. Provision of such entertainment was a welcome diversion for passengers, particularly in long trips such as transoceanic flights.
Video entertainment systems on aircraft typically utilize a movie screen or screens or a relatively large video monitor or monitors installed in centralized locations in the passenger cabin for simultaneous viewing by multiple passengers. Such systems allowed for video display of films as well as instructional videos such as flight safety information. However, these systems require all passengers to simultaneously watch a single video selection at a scheduled display time. Moreover, such systems are limited to passive video entertainment such as feature films.
More recently, systems have been developed which mount relatively small video monitors on the back of passenger seats for viewing by the passengers in the seats immediately behind such video monitors. Video monitors could also be mounted on arm rests. By utilizing a dedicated video monitor for each passenger, these systems allow for a passenger to choose from several simultaneously broadcasted video signals, thus allowing the passenger, for example, to select one of several available films. The films are generally provided at a centralized location on videotape recorders and are simultaneously broadcast over the system. These systems typically employ architectures which distribute the video signals to the passenger on a seat column, daisy chain distribution path. Several video signals are typically broadcast on the distribution path as either baseband or multiplexed signals. Accompanying the passenger seats is a tuner or switch which allows the user to tune or switch into the selected video broadcast.
These systems suffer from several disadvantages. Initially, the entertainment videos are simultaneously broadcast at scheduled times. Thus, while the user can select from several video offerings, the user is still required to conform viewing to the scheduled time. Additionally, by placing sufficient electronic resources at each passenger seat to tune or switch the broadcasted signals, several disadvantages result. This tuning or switching capability results in excessive heat generating at the site of each video monitor. In a sealed aircraft cabin with tuners or switches contained at each passenger seat, this excessive heat not only provides difficulties for the aircraft cooling system, but also results in reliability problems as overheated equipment is more prone to failure. Additionally, placement of tuners or switches at each passenger seat adds weight to the aircraft and cramps the passenger seat area.
Further, the traditional daisy chained distribution path has multiple drawbacks. If a breakdown occurs in the daisy chain distribution path, all users downstream of the breakdown can be adversely affected. This can result in a significant percentage of video monitors that are out of service at any given time.
Still more recently, systems have been designed which attempt to provide passengers with interactive capabilities such as video games. These systems utilize a multi-drop communications link to provide the user with the interactive capabilities. While these systems offer greater passenger choice and convenience, several disadvantages result. The provision of two-way data flow to provide interactive capabilities results in additional expense as complicated data protocol and addressing networks are required to allow for the broadcasting and receiving capabilities of the system. This also can result in excessive electromagnetic interference and radio-frequency interference within the aircraft cabin which can cause disturbances in the aircraft's avionics. Additionally, use of a multi-drop communications link for interactive video can cause data bottlenecks and long response times during peak usage.
In addition to the tuning or switching resource, systems in the prior art place some of the interactive data sources at each passenger seat. At any given time only a small percentage of these data sources will be in use. For example, in a 400 passenger seat aircraft, 400 of each resource will be provided. At any given time, only a small number of these resources will be in use. Idle resources at one seat are unavailable to any other passenger so duplicative over capacity is provided.
By locating the data sources at each passenger seats, the electronic resources at each passenger seat location are increased resulting in even higher heat generation, weight and cost. Maintenance is costly because if a video source malfunctions, the passenger in that particular seat cannot utilize that video source until it is fixed, and it must be fixed immediately in an unscheduled maintenance or the seat will fly "dark." Thus, special maintenance is required to fix each video source individually. Additionally, if a video source placed at the passenger seat becomes obsolete, updating entails replacing multiple installations at each passenger seat which is both costly and results in unacceptable aircraft down time. The cost and time needed to replace multiple installations also results in a system with little flexibility as to offered entertainment sources. The variety of interactive systems also is constrained by the amount of hardware that can fit into a seat back.
What thus is needed is a system which efficiently provides for multiple entertainment sources to video monitors located at passenger seat locations while avoiding the drawbacks of the systems of the prior art. In particular, such a system should avoid generating excessive heat in the aircraft cabin both to lessen the burden on the aircraft cooling system and to increase the reliability of the system. The system should reduce the weight requirements and the seat clutter of the systems in the prior art. The system should reduce data bottlenecks and long response times during peak operation. The system also should reduce the occurrence of electromagnetic interference and radio frequency interference in the aircraft cabin. The system should improve the reliability and simplify the maintenance and updating requirements to improve service to the user and to reduce costly aircraft down time. The system should allow for flexibility in the choice and number of offered entertainment sources.